Positioning and nerves Flashcards
Which reflex activates the SNS when going from sitting to standing?
baroreceptor
How does general anesthesia affect the baroreceptor reflex and SNS tone?
Decreases
What does positive pressure ventilation do to intrathoracic pressure and venous return?
Increases intrathoracic pressure and decreases venous return
Same with PEEP
Frank starling curve with positions
Does placing the patient in Trendelenburg improve hypotension?
Latest evidence says no
Should shoulder braces be used?
No
Use a non-slip mattress
To prevent a brachial plexus injury, shoulders should be less than?
<90 degrees
Don’t let shoulders sag forward when prone
How can you assess for thoracic outlet syndrome?
Have the patient clasp her hands behind her head, if it hurts then you may need to tuck arms when prone
Where is an axillary roll placed?
Caudad to the axilla or (distal)
Where should a retaining strap be placed across the hip?
Between the iliac crest and the head of the femur. NOT directly over the head of the femur
What is the most commonly injured nerve?
Ulnar
Two ways the ulnar nerve is injured.
Excessive flexion
External compression
best way to position arm to prevent ulnar injury
What is claw hand?
Ulnar nerve injury
Impaired sensation to fourth and fifth digits
Inability to ABduct or oppose the pinky finger
Are sensory or motor nerve injuries more common? More serious?
Sensory are more common and less serious
Which nerve is likely to be injured during an IV insertion in the antecube?
Median nerve
Elbow hyperextension can injure which nerve?
Median nerve
Hand benediction or ape hand are injuries to which nerve?
Median nerve
Sensory for the median nerve includes? Motor?
Sensation to the palmer surface of the thumb, index finger, middle finger, and lateral of the ring finger
Motor - inability to oppose thumb
Which nerve is most likely injured by an IV pole pressing on the humerus?
Radial
Sheets tucked too tight can cause which nerve injury?
Radial
Excessive BP cuff cycling can cause nerve damage to which nerve?
Radial
Wrist drop is a sign of which nerve injury?
Radial
Dull shoulder pain is a sign of which nerve injury?
Suprascapular nerve
Scapular winging is a sign of which nerve injury?
REMEMBER SALT (serratus anterior long thoracic)
Long thoracic nerve
Innervates the serratus anterior
Foot drop is a sign of which nerve injury?
Common peroneal
Inability to evert the foot is a sign of which nerve injury?
Common peroneal
Inability to extend the toes dorsally is a sign of which nerve injury?
Common peroneal
Which nerve is injured in stirrups when the medial aspect of the leg is compressed?
Common peroneal
What nerve allows you to adduct the leg?
Obturator
The femoral nerve arises from which plexus which roots?
Lumbar Plexus
2,3,4
Which nerve is blocked during an adductor canal? Where does the nerve rise from?
Saphenous
Branch of the femoral nerve
What does the saphenous nerve innervate? What can injure it? Presentation?
Medial aspect of the lower leg
Lithotomy - leg pressed against
Presentation- reduced sensation on anteromedial aspect of leg (lower leg)
Adductor canal is good for which surgeries? What nerve is blocked?
ACL
MCL
Patella
Vein stripping
Saphenous nerve
Which plexus innervates the ankle except for one nerve?
Which LE nerves are only sensory?
Lateral femoral cutaneous
Saphenous
Sural
LE innervation
Clinical assessment of LE
Which nerve allows for hip flexion?
Femoral
Which nerve allows for hip extension?
Sciatic
Which nerve allows for knee flexion?
Sciatic
Which nerve allows for hip extension?
Femoral
Which nerve allows for plantar flexion?
Tibial
What happens if a patient’s legs are crossed during surgery? Which nerves are injured?
Top leg - sural nerve (it’s on the underside of the leg)
Bottom leg - superficial peroneal nerve
What does the Pudendal nerve innervate? Which plexus does it come from?
Innervates the perineum
Comes from sacral plexus
Extreme hip flexion can cause injury to which nerve?
Sciatic
Extreme external rotation of the legs can injure which nerve?
Sciatic
Foot drop is a sign of which nerve injuries?
Common peroneal and sciatic
Inability to evert the foot is an injury to which nerve?
Common peroneal
Inability to extend the toes dorsally is an injury to which nerve?
Common peroneal
Minimizing hip flexion will protect which nerve?
Obturator
A popliteal nerve block will block which nerves? Where do they rise from?
It will block the tibial nerve and the common peroneal nerve right as they branch from the sciatic nerve
What position is compartment syndrome most seen in? treatment?
Lithotomy
Fasciotomy
Hyperextension (hyperlordosis) in the supine position can cause what?
paraplegia
What causes Midcervical tetraplegia?
Hyperflexion of the neck around C5
Most common in the sitting position
2 fingers should between chin and chest
Also seen in tracheal resections
What are the 4 T’s likely to occur in the anterior mediastinum?
Thymoma
Teratoma
Thyroid
Terrible lymphoma
Best way to induce a mediastinal mass?
Spontaneous ventilation awake
Sitting position
IF the airway collapses during intubation of a mediastinal mass, what steps should you take?
Lay patient lateral or prone
Crash onto bypass
Which three things worsen tracheobronchial compression?
Supine
Induction of GA
PPV
Which two procedures increase the risk of midcervical tetraplegia?
Tracheal resection
Crani in the sitting position
Which position increases the risk of suprascapular nerve injury?
Lateral
Which position has the highest chance of creating airway edema?
Steep trendelenburg
Which positions shift blood towards the central circulation? What about away?
Towards - Trendelenburg and lithotomy
Away - sitting, lateral
Which way does sitting and lateral shift the frank starling curve?
To the left (more towards the peripheral)
Which way does Trendelenburg and lithotomy shift the frank starling curve?
To the right (more towards central)
Which positions reduce cardiac output the most?
Sitting
Prone
